Working principle and classification of hydraulic down-the-hole drilling rig
Hydraulic down-the-hole drilling rig, everyone may hear that there are not many machines and equipment. It is a kind of drilling machinery and equipment, which is commonly used in urban construction, railway lines, roads, river banks, hydropower projects and other engineering projects. Rock pre-stressed anchor cable hole, anchor cable hole, engineering blast hole, grouting hole and other drilling engineering construction.;
The principle of hydraulic down-the-hole drilling rig is the same as that of a general impact rotary pneumatic rock drill. The air-driven rock drill combines the impact rotation organization, and the impact energy is transmitted to the twist drill according to the drill rod; while the DTH drill separates the impact organization (impacter) out and dives into the bottom of the hole. No matter how deep the hole is, the twist drill is all It is immediately installed on the impactor, and there is no need to transmit impact energy according to the drill pipe, so the damage of impact energy is reduced.
Hydraulic down-the-hole drilling rigs' rock drills are accompanied by the improvement of drilling depths, and the damage to the drilling ability at the submersible rods, connectors (medium-deep hole drilling), etc. has increased, the drilling rate has been significantly reduced, and the cost has increased. In order to better reduce the damage to work capacity and improve the efficiency of drilling, down-the-hole drilling rigs have been designed in specific engineering projects. The down-the-hole drilling rig also uses air compression as the driving force, rotating impact and crushing rocks to form piles. The principle is that the inclination impactor of the down-the-hole drill is connected to the twist drill and installed in front of the drill rod. The rock at the bottom of the hole touches; the rotating organization makes the drilling equipment continue to rotate, the impactor installed in front of the drill rod, under the effect of air compression, makes the piston rod impact the twist drill back and forth to impact the rock; the air compression is from the rotary tunnel The ventilation organization enters and passes through the hollow rod to pass through the bottom of the hole, and the crushed rock dust is discharged from the annular indoor space between the drill rod and the edge of the hole into the hole. It is not difficult to see that the essence of down-the-hole drilling is that under the effect of radial working pressure, the two ways of crushing rock, impact and rotation, are fusion, in which the impact is interrupted, the rotation is continuous, and the rock is impacting and shearing. Continuously damaged and cut off under the effect of shear stress. In DTH drilling, impact work plays a dominant role.
